1. Field of the Invention
This invention relates to a navigation device using digital map information, a digital map display system for displaying digital map information, and a digital map displaying method in a navigation device.
2. Description of the Related Art
Recently, navigation devices which can find their own positions and traveling speeds in real time by using GPS (Global Positioning System) satellites orbiting up in the skies have been becoming popularized for being carried on a mobile unit such as an automobile or for portable use. In such navigation devices, electronic map data is used and a map is displayed on its monitor on the basis of the map data. Moreover, the position where the user is, positioned by the GPS, and a traveling route for guidance and the like are displayed in an overlapping manner on the map.
Some of such navigation devices have a function to display a list of user-registered indexes so that the user can easily search for a predetermined spot. This user-registered indexes include spot information stored in a database within the navigation device by the user""s operation. For example, in the case of guidance by the navigation device, the spot information includes the history of a spot set as a destination spot, the history of spot information extracted as a result of telephone number search, address search, name search and coordinate search carried out by the user, information of a spot registered by the user, and so on. As the indexes of such spot information are displayed in a list to the user and the user selects an index indicating a predetermined spot from the list, the user can easily find out the predetermined spot.
However, the indexes of the list displayed in the above-described technique are simple information such as telephone number, address, latitude and longitude, and place name indicating the vicinity of the predetermined spot. For example, if no specific name or place name is appended to a spot extracted by telephone number search, only the telephone number is displayed as its index. Similarly, if no specific place name is appended to a spot registered by scrolling a map and using a pointer, only the latitude and longitude of the spot are displayed as its index. Therefore, information about what meaning the spot has or what kind of facility it is, is not displayed. As a result, when a list is displayed, the user must search for a predetermined spot on the basis of only the simple information from the list and it takes a long time to find out the predetermined spot.
In view of such a technique problem, it is an object of this invention to provide a navigation device and the like which enables the user to effectively search for a predetermined spot.
In order to achieve the above-described object, a navigation device according to this invention is adapted for displaying a positioned current position and a digital map based on map data made up of electronic information, and comprises registration means for registering an index designated by a user""s operation and data of a spot coordinate in association with each other, and display means for displaying a plurality of registered indexes as a list. The display means displays, together with the list, a digital map of a spot coordinate corresponding to an index selected from the indexes.
In this navigation device, as the digital map of the spot coordinate corresponding to the selected index is displayed together with the list, it is possible to inform the user of spot information about the index. The index is a name provided to each of the registered spot coordinate data, for example, spot name, landmark name, telephone number, address, coordinate and the like. The positioning of the current position in the navigation device can be carried out, for example, on the basis of signals sent from a plurality of GPS satellites.
This navigation device may further comprise extraction means for extracting the digital map of the selected index from the map data on the basis of the data of the spot coordinate.
The display means may also display additional information about the vicinity of the spot coordinate together with the digital map. In this case, the additional information is information such as weather information acquired from outside via a network.
This invention also provides a digital map display system. This digital map display system is adapted for displaying a digital map based on map data made up of electronic information, and comprises registration means for registering an index of a predetermined spot in the digital map in accordance with a user""s operation, and display means for displaying a plurality of registered indexes in response to a request from the user. The display means displays an image associated with a predetermined index selected by the user from the indexes, together with the plurality of indexes displayed by the display means.
In this digital map display system, for example, the registration means may register data of the spot coordinate of the predetermined position together with the indexes, and the display means may display a digital map extracted from the map data on the basis of the spot coordinate.
Moreover, this invention also provides a digital map displaying method in a navigation device. This digital map displaying method is adapted for the user in a navigation device for displaying a positioned current position and a digital map based on map data made up of electronic information, and comprises a step of registering an index designated by a user""s operation and data of a spot coordinate in association with each other to a database, a step of displaying the index as a list, a step of reading, from the database, data of a spot coordinate associated with a predetermined index selected from the list, a step of extracting map data corresponding to the data of the spot coordinate thus read, and a step of displaying a digital map based on the map data together with the list.
Preferably, the step of displaying the digital map includes setting the display of the digital map together with the list in such a manner that the spot coordinate is substantially at the center of the digital map.
Furthermore, this invention also provides a program executed in a navigation device.
Thus, according to the present invention, the user can easily find out an index indicating a predetermined spot from a plurality of registered indexes.